A tiny Wall Street firm advising Pfizer on its giant deal has had an incredible year

Guggenheim Partners executive chairman Alan Schwartz. REUTERS/Danny Moloshok It has been a good year for Guggenheim Securities.

The 16-year-old firm has been an adviser on five massive transactions in what has been one of the busiest years for mergers and acquisitions on record.

Its biggest deal yet, Pfizer's $160 billion deal with Allergan, was announced on Monday.

Guggenheim Securities is one of three boutiques advising Pfizer on the inversion deal.

The others are Moelis and Co. and Centerview Partners. Goldman Sachs is also advising Pfizer on the deal.

As the investment bank has expanded further into sectors that Wall Street's biggest banks count on for M&A revenue, it has also taken key talent from top advisers elsewhere in the investment-banking business.

This includes Fares Noujaim, who was a star banker under Guggenheim executive chairman Alan Schwartz when they worked at Bear Stearns, and Jeff Hoffman and Joseph Kohls, healthcare-sector veterans from JPMorgan and Bank of America Merrill Lynch, respectively.

Here is a breakdown of the 10 biggest deals for the bank, as tracked by the M&A data provider Dealogic — many of them from the past 12 months — that have increased Guggenheim's clout in the banking world.

Deal: Big pharmaceutical deals have become a staple at Guggenheim Securities, and in 2010 its biggest mandate — in any sector — at the time was Merck KGaA's deal to acquire the Massachusetts-based life-sciences firm Millipore in a $7 billion transaction. Guggenheim and Perella Weinberg advised Merck on the deal.

Deal: Guggenheim has been on both sides of big deals for Verizon. The boutique bank advised the telecom giant when it dealt wireline assets to Frontier Communications in a deal worth more than $10.5 billion to start 2015. Guggenheim worked alongside PJT Partners and Credit Suisse. The deal was announced in February.

Merck snapped up a US competitor for about $17 billion in 2014.

Deal: Merck added to its life-sciences products in 2014 by spending nearly $17 billion to buy Sigma-Aldrich, according to Dealogic data. Guggenheim and JPMorgan advised Merck on the deal.

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Guggenheim advised Pfizer on another big deal earlier this year.

Thomson Reuters

Sector: Pharmaceutical

Deal: Pfizer announced plans in February to buy its competitor Hospira, one of the first in a series of big deals for Guggenheim in 2015. The deal was worth $18 billion, according to the data provider Dealogic. Advising Pfizer alongside Guggenheim was Lazard and JPMorgan.

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Many of Guggenheim's largest mandates — including the September sale of Cablevision to private investors — have come in 2015.

The Chubb insurance deal was a big day for Guggenheim.

Deal: Chubb in July announced its sale to the insurer Ace Ltd. in a $28.9 billion deal. The transaction was a big deal for Guggenheim, which locked in the exclusive role advising the target.

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Guggenheim claimed a mega-mandate on the Time Warner Cable-Charter deal.

Joshua Lott/Reuters

Sector: Telecommunications

Deal: After Time Warner Cable's plans to sell itself to Comcast fell apart because of regulators' concerns, Charter Communications swooped in to buy out the target. The deal was announced in May. It was a big deal for Guggenheim, which joined LionTree Advisors and Goldman Sachs in advising Charter on the $79.5 billion deal.

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Guggenheim took a big fee on Verizon's stake buyback from Vodafone.

YouTube/Verizon

Sector: Telecommunications

Deal: Verizon in 2013 acquired the stake it didn't already own in the wireless joint venture Verizon Wireless from Vodafone in a $130 billion deal. Guggenheim advised Verizon on the transaction alongside JPMorgan Securities, Morgan Stanley, and Paul J. Taubman.

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Guggenheim advised Pfizer on its Allergan acquisition, the biggest in 2015.

Fares Noujaim.
Wikimedia Commons

Sector: Pharmaceutical

Deal: And now Guggenheim Securities has landed its biggest advisory mandate ever, working as an adviser on the $160 billion Pfizer-Allergan deal. Guggenheim advised Pfizer alongside Goldman Sachs, Moelis and Co., and Centerview Partners in the biggest M&A deal in the US this year.